Planning difficulty and temporal constraints differently shape the level of detail and ordering of visual exploration

Abstract

Planning entails identifying sequences of actions to reach a goal, but how much of a future plan is constructed before movement and how visual exploration supports this process remain poorly understood. Here, we investigated how visual exploration before and during action relates to the executed path and how this relationship is shaped by task difficulty and temporal constraints. Participants solved a path-finding task while their gaze and navigation movements were recorded. We manipulated planning difficulty using misleadingness, which captures the mismatch between the perceptual layout of a problem and the structure of its solution, and manipulated temporal constraints by either allowing immediate movement or imposing a temporal delay. We quantified how visual exploration covered the executed path (spatial coverage) and retained its sequential organization (temporal coherence). Greater difficulty increased visual exploration, repeated sampling, and spatial coverage, but was associated with lower temporal coherence with the upcoming path. When participants could act immediately, pre-movement visual exploration showed lower spatial coverage than during execution. Imposing a delay increased pre-movement spatial coverage, bringing it closer to the level observed during execution, but did not increase temporal coherence. The delay was also associated with fewer pauses and backtracks, suggesting that plans were better consolidated before movement, reducing the need for online revision. Individual differences reflected continuous variation in the balance between pre-movement planning and online revision. Together, these findings suggest that participants flexibly allocate visual exploration before and during plan execution, adjusting its level of detail and ordering to problem difficulty and temporal constraints.